1. Field of the Invention
The present invention relates to a fan, and relates to a bearing structure of the fan.
2. Description of the Prior Art
Fans are usually used in dissipating heats generated by interior electric components during operation all the time. A conventional fan shown in FIG. 1 includes a stator and a rotor. The stator includes a base 12 and a ball bearing 14 disposed inside the base 12. The base 12 and the ball bearing 14 support the shaft 16 of the rotor together. The ball bearing 14 includes an inner ring and an outer ring rotating relative to each other. The outer ring urges against the base 12, and the inner ring urges against the shaft 16. Therefore, the cooperation elements must allow certain of deformation to achieve a tight press. However, the deformation causes the variation of the size of the element, and causes a non-uniform stress induced by the element. During the fan operation process, the inner ring of the ball bearing 14 rotates corresponding to the shaft 16 so as to generate heat because of the friction, and the heat will enlarge the variation. Additionally, when the shaft is in operation, the size of the shaft varies because of heats, and the abrasion becomes serious, such that the lifetime of the shaft and the ball bearing is lowered. Therefore, after the fan operates in a period of time, the stability of the fan will be lowered by the variation.